1. Technical Field
Embodiments of the invention relate to semiconductor devices performing a data bus inversion (DBI) operation and a data masking (DM) operation and semiconductor systems including the same.
2. Related Art
In a semiconductor system including a controller and a semiconductor device, a read operation or a write operation may be performed by transmission of data between the controller and the semiconductor device. During the read operation, data stored in the semiconductor device may be transmitted to the controller. During the write operation, data outputted from the controller may be transmitted to the semiconductor device and may be stored in a memory area of the semiconductor device. A data masking (DM) operation may be used to store only desired bits among bits of the data outputted from the controller into the memory portion of the semiconductor device. That is, if the DM operation is performed, the semiconductor system may store only desired bits among the data outputted from the controller in the semiconductor device or may prohibit the desired bits among the data from being stored in the semiconductor device.
Meanwhile, if the number of data bits whose phases are changed when the data are transmitted in the semiconductor system increases, a simultaneous switching noise (SSN) phenomenon and an inter-symbol interface (ISI) phenomenon may occur more frequently. Thus, a data bus inversion (DBI) scheme has been used to suppress the SSN phenomenon and the ISI phenomenon. In the event that data outputted from the controller are transmitted to the semiconductor using the DBI scheme, the data have to be transmitted together with a DBI signal including information on whether the data are inverted.